Feed-water heater



Sept. 25, 1923, 1,469,068

R. N. EHRHART FEED WATER HEATER Original Filed Sept. 18. 1918 Fit/i WITNESSES: OR-

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UWTEE STATES ear-ear "errata,

RATMONJD N. EEEHABT, 018 EDGEWOOD, rnnnsrnvanra.

ramp-warns; nnarnn- Applicntion illed deptember 18, 1918, Serial It'o. 254,661. Renewed may 23, 1922. serial Ito. %,2t2.

Allegheny and State of Pennsylvania, have made a new and useful Invention in Feed- Water Heaters, of which the following ,is a specification.

This invention relates to feed water heatcrs. It has been found that high efliciency in powercycles is obtained by serially heat ing feed water up to, or nearly up to boiler pressure.

An object of this invention is to produce an improved system for feed water heating, by which the feed water is heated to approximately boiler pressure, and the quantity of heating fluid is to some extent, proportioned to the amount of feed water to be heated. 1 I

A further object is to produce a simple, compact, eliicient and comparatively inexensive feed water heater, capable of raismg the temperature of the feed water 'to approximately that of the water in the boiler.

A further object is to produce an improved feed water heater provided with a series of heating chambers through which the feed water is adapted to pass serially, and in connection with which, means are employed for delivering steam of progressively higher temperature to the successive, chambers of the series, whereby unheated feed water passes first through the chamber of lowest temperature, abstracts additional heat from each chamber as it progresses through the series, and is finally delivered from the heater chamber having the highest temperature.

Another object is the production of a feed water heater wherein, converging or diminishing heat distributing areas are presentedto the incoming heating fluid or steam, so as to obtain maximum heat transfer with a minimum of tube area.

One embodiment of the invention is illustrated in the accompanying drawings where- Fig. 1 is a diagrammatic vertical sectionalview of a feed water heater shown in connection with a multistage steam turbine.

Fig. 2 is a diagrammatic horizontal sectional view of a steed water heater and pump.

The heater illustrated mcludes a rectangular shell provided with partitions so arimproved water heater.

ranged as to divide the rectangular cham= ber Within the shell into separate triangular heating chambers in which the heatin sur face is so distributed as to obtain hig -chiciency in accomplishing the heat transfer from the heating fluid to the water to be heated traversing the tubes of the heater.

As illustrated, the rectangular shell 1, is rovided with three partitions 2, 3 and a, which are so arranged as to divide the interior of the shell into four separate triangular chambers A, B, C and D. The interior of the shell is also provided with longitudinally extending tube plates5 and 6, which in conjunction with the partition 2, 3 and Al 0 by means of a pump 9 which may be of anypreferred form. In the apparatus illustrated, the water boxes 6, f, g, h and i are so arranged that feed water an the box 6 will pass through the water tubes 7 of the chamber A, to the box I, thence through the water tubes of the chamber B to the box I in which the direction of flow is reversed and the water is delivered to the tubes of the chamber G, through which it passes into the box I. The direction of water flow is again reversed in the box hand the water then passes through the tubes of the chamber D,

into the water box z, and is delivered from the heater by, the passage 10.

It is well known that very efiicient power cycles in steam operations are obtained by heatihg the feed up to or nearly up to boiler temperature, and in the drawings 1 have illustrated means for accomplishing this with high efliciency in connection with my In Figure 1 of the drawings, I have diagrammatically illustrated a turbine 11 of the multi-stage type, to which high pressure steam is supplied through the inlet port 12. Steam entering the inlet 12 is delivered to the first or initial stage 14, where it is partially expanded and from which it passes through successive expansion stages 15, 16 and 17, and finally is delivered into the exhaust casing 18, from which it may be discharged into a condenser which it not shown.

It is an object of this invention to produce means for raising the temperature of the feed water i in steps, as it passes serially through the heating chambers A, B, C and D in the manner previously described. As shown, the heater bhambers A, B, C and D are respectively connected with pressure stages 17 16, 14: and the inlet port 12 by the respective passages A, B, C and D, with the result that the chamber A is maintained at substantially the temperature of the steamin the stage 17 which is lower than the temperature of the steam traversing the preceding stages, and chamber D is maintained at substantially the temperature of steam at boiler pressure, since unexpanded steam 1S supplied to it from the inlet port 12 of the turbine. The temperatures in the intermediate chambers B and C substantially correspond to the temperatures in the stages 16 and 1% respectively.

It will be seen therefore, that the feed water in passing serially through the chamhers A, B, C and D in the order named, encounters a hi her temperature in each succeeding chamher, and the heat of the steam is abstracted to the best advantage, the feed Water emerging from the heater with a temperature approximating the temperature 1n the chamber D, or the temperature of the water in the boiler.

The condensate resulting from the contact of the heating steam with the cooler tubes 7 of the heater drops to the bottom of the chambers and is extracted by means of a series of steam traps J which are connected to the various chambers A,.B, G and l) by means ofcondensate delivery pipe J Each of the chambers A, B, C and D is shown provided with an atmospheric vent 19 for relieving the heater in case it becomes air bound. It will be understood that these vents areprovided with suitable valves conforming to closed heating practice.

Referring to Fig. 1, it will be seen that the tubes in each triangular chamber A, B, C and D are arranged so that there is a diminishing number of tubes in the horizontal rows of tubes from the heating fluid inlet end of the chamber, thus presenting a diminishing heat transfer area' tTrthe inflow of heating steam as it flows through the nest of tubes. The number of tubes and the area thereof, is preferably such, that the area is reduced substantially in inverse proportion to the condensation taking place along the path of steam flow, the purpose being to so distribute the heat transfer surface, that a minimum number of tubes are employed in each chamber and each tube in each chamber occasions the same heat transfer as each of aeeaoee flow through the heater can be increased bythe multi-pass arrangement illustrated and described, and this adds to the efliciency of the heater by increasing the heat transfer accomplished in each chamber,

While I have described and illustrated but one embodiment of my invention, it will be apparent to those skilled in the art that various changes, modifications, additions and omissions may be made in the apparatus described and illustrated without departing from the spirit and scope of the invention as set forth by the appended claims.

What I claim is:

1. A feed water heater comprising a plu-- rality of triangular heating chambers, each having an inlet through which heating fluid is supplied to the chambers, and each receiving fluid having a different temperature, and a feed water passage extending serially through the heating chambers, including a series of parallel tubes arranged in each compartment in diminishing number from the heating fluid inlet, through which tubes the feed water is adapted to be circulated.

2. A feed water heater comprising a rectangular shell, diaphragms in the shell dividing it into a plurality of triangular heating chambers, means for delivering heating fluid to each of the heating chambers at a point near the large end of the chamber, and a sub-divided feed water passage extending through the chambers having a diminishing heat absorbing area from the large end toward the apex of each chamber.

3. A feed water heater comprising a shell, partitions extending across the interior of the shell and dividing it into a series of separate heating chambers, means for delivering a separate supply of heating fluid to each of said chambers, feed water passages extending through each of said heating chambers, means for connecting the feed water passages of each chamber with feed water passages of at least one other chamber whereby the feed water successively passes through different heating chambers of the series, and means for delivering condensate from each heating chamber.

4. A feed water heaterv comprising a substantially rectangular shell, partitions extending across the interior of the shell and dividing it into a series of heating chambers, feed water passages extending through each of said heating chambers, means for connecting the feed water passages of each chamber with the feed water passages of adjacent chambers whereby feed water passes successively through the successive chambers neeaoee of the series, means for delivering heating fluid of progressively increasing temper-- ature to the successive chambers of the series, and means for venting non-condensible gases from each chamber of the series.

5. A feed Water heater comprising a shell, divided into a series of heating chambers, a sub-divided feed Water passage extending serially through said chambers and including a series of tubes arranged in each chamber, means for delivering heating fluid at different temperatures to different chambers of the series, means for delivering non-condensible fluid and condensate from each chamber.

'6. A feed Water heater comprising a substantially rectangular shell, divided into a series of separate heating chambers, a subdivided feed water passage extending serially through said chambers and includin a series of tubes extending through eac compartment, means for delivering heating fluid at progressively increasing temperatures to the successive chambers of the series, and means for Withdrawing condensate and ncn-condensible fluid from each chamber of the series.

7. A. feed Water heater comprising a shell, partitions extending across the interior of and water boxes the shell and dividing the interior thereof into a plurality of heating chambers and Water boxes, feed Water tubes Within each heating chamber, and openings at opposite ends into separatewater boxes, said tubes being so arranged that feed Water passes serially through the successive heating chambers, means for delivering heating fluid to each chamber, means for delivering condensate from each chamber and means for venting non-condensible fluids from each chamber.

8. A feed water heater comprising a shell, partitions dividing the interior of the shell into a plurality of separate heating chambers, each having an inlet port for heating fluid and an outlet port for condensate, feed Water tubes traversing each chamber, means for connecting the tubes of each chamber with tubes of at least one adjacent chamber whereby feed Water passes serially through tubes of successive chambers, and means for delivering heating fluid of difi'erent temperatures to different heating chambers.

In testimony whereof, it have hereunto iubscribed my name this 14th day of Sept,

RAYMOND n. EHRHART. 

